This project consists of four related areas of investigation, all concerned with the analysis of mechanisms of attention. Special emphasis is placed on the use of lesion and/or biochemical techniques to elucidate mechanisms involved in visual attention. The four areas are: (1) attention and cerebral mechanisms of visual behavior; (2) pharmacological mechanisms of attention; (3) brain activity in inattention: local cerebral glucose metabolism in sleep; and (4) the design of a general attention task.